Device for clearing landmines

ABSTRACT

The invention concerns a device mounted on a carrier vehicle equipped with at least a support ( 4 ) whereon a frame ( 6 ) is mounted in articulation, with interposed a pressure actuator ( 8 ), the frame being equipped at its bottom end with a plurality of vertical bars ( 24 ) whereof the lower ends ( 26 ) are provided with feet ( 28 ) and whereof the upper ends are provided each with a piston ( 15 ) mounted sliding into a cylinder ( 13 ). A mechanical component ( 10 ) called a proportioning unit, wherein are arranged the cylinders ( 13 ) used for fixing the pistons ( 15 ) disposed at the upper ends of the bars ( 24 ), and comprising a chamber ( 14 ) communicating said cylinders, is mounted sliding between stop elements ( 12, 13 ) in the frame, parallel to the axes of the cylinders ( 13 ), the mechanical component forming a proportioning unit ( 10 ) is directly subjected to the action of the thrust forces of the actuator ( 8 ) via the frame stops ( 12 ).

[0001] The subject of the present invention is a device for neutralizing a minefield and, in particular, a field which may contain anti personnel mines.

[0002] Neutralizing or clearing a field consists in removing the mines from the field or in destroying them in situ.

[0003] Among the methods used, mention may be made of destruction by mechanized vehicles in readily accessible areas and manual detection in areas where access is more difficult. The latter method is slow and dangerous.

[0004] Document WO/JP99/01909 relates to a device for neutralizing a minefield comprising a carrier vehicle, such as a loader or hydraulic digger, equipped with at least one support to which a chassis is articulated with the interposition of a pressure actuator, the chassis being equipped at its lower end with a plurality of bars, the lower ends of which are equipped with feet. The various feet arranged, for example, in a rectangle, rest against the ground, and the material covering the mine or mines, if a mine is present, is compacted, thus causing the mines to be destroyed by explosion. According to one embodiment of the device described in the aforementioned document, the vertical bars have upper ends each provided with a piston mounted to slide in a cylinder, the various cylinders communicating and being filled with an incompressible fluid. A vibration generator such as a piston with reciprocating movement vibrates the fluid thus transmitting this vibration to the bars bearing the various feet resting on the ground. The pressure of the actuator mounted between the support and the chassis is also transmitted to the bars and to the feet via the incompressible fluid. The effectiveness of such a device is mediocre, in that all the forces are transmitted through the incompressible fluid, and this device is fairly ill-suited to uneven ground, in that all the bars are parallel with no possibility of orientating with respect to one another.

[0005] The object of the invention is to provide a device for neutralizing, a minefield able effectively to transmit the pressure forces and vibration to the feet resting on the land so as to reliably destroy a mine buried in this land, and to allow the position of the bars and of the feet to adapt to the configuration of the land, if the land is uneven.

[0006] To this end, the device to which the invention relates, of the type mounted on a carrier vehicle equipped with at least one support to which a chassis is articulated with the interposition of a pressure actuator, the chassis being equipped at its lower end with a plurality of vertical bars the lower ends of which are provided with feet and the upper ends of which are each provided with a piston mounted to slide in a cylinder, the various cylinders communicating and being filled with an incompressible fluid subjected to the action of a vibration generator contained in the chassis, is characterized in that a mechanical part known as a proportioning device, in which the cylinders used for mounting the pistons arranged at the upper ends of the bars are formed and which incorporates a chamber for placing these cylinders in communication, is mounted to slide between stops in the chassis, parallel to the axes of the cylinders, the mechanical part forming a proportioning device being subjected directly to the action of the pressing forces of the actuator, via the stops of the chassis.

[0007] The proportioning device can slide freely between stops secured to the chassis in the same axial direction as the bars. As a result, the axial pressing force produced by the actuator is transmitted directly to the chassis, then to the proportioning device and finally to the pistons, bars and feet, via the fluid contained in the cylinders of the proportioning device.

[0008] According to another advantageous feature of the invention, the proportioning device is in direct contact with the vibration generator which transmits vibration parallel to the axis of the cylinders. The fact that the vibration produced by the generator is transmitted directly to the proportioning device improves the effectiveness of the device.

[0009] The combination of the vibration and of the pressing force generated produces the desired compaction of the material covering the mine or mines, causing them to be destroyed by explosion.

[0010] According to one feature of the invention, each piston rod is articulated via a universal joint to the upper end of a bar, longitudinal spring leaves fitted to the rod bearing on the bar to keep it aligned with the rod in the absence of external influences. As the feet themselves are mounted at the lower end of a bar via a universal joint, it is possible for the lower part of the bars to incline with respect to the upper part thereof in order to adapt to the lie of the land.

[0011] Furthermore, each bar bearing a foot is made as two rigid parts, that is to say an upper part mounted on the piston rod and a lower part or rod which, fixed rigidly and removably in line with the upper part, is made of a readily-breakable and low-cost material.

[0012] These features allow the apparatus to be protected from the destructive effects of the explosion. What happens, in the case of the explosion or a mine, is that only the lower part or rod of the bar will be destroyed, especially as the inclination of the rod carrying a foot, with respect to the corresponding bar, reduces the transmission to the piston of the destructive effects of the explosion, since, in this position which is inclined with respect to the main direction of the explosion, the rods are readily breakable. These lower rods which are made, for example, of a synthetic substance or bamboo, are wearing components which are very readily replaceable actually in the field that is to be made safe.

[0013] According to another feature of the invention, each piston rod is prevented from rotating with respect to the cylinder in which the piston it bears is moveably mounted.

[0014] As a preference, each piston rod is subjected to the action of a spring exerting, on the rod, an upward vertical action so as to align the feet of the various bars when no influence is exerted on the bars. This realignment is important when the chassis is raised to move from a region which has been made safe to an adjacent region.

[0015] According to one embodiment of this device, the feet are joined to one another by flexible links, the feet arranged at the periphery themselves being connected by such links to a frame or casing that extends the chassis downward.

[0016] When the field conditions so permit and when the work rate can be increased, it is possible to make the feet slide along the ground in an overall movement of the apparatus which is generated by the movement of the arm or of the carrier vehicle, while at the same time maintaining the pressure of the actuator and generating vibration. The securing of the various feet, at least in the direction of travel, using flexible attachment means allows this movement while at the same time allowing the feet to retain their independence in a vertical direction. Depending on the lie of the land, it is possible to juxtapose several modules such as the one which has just been described, so as to increase the neutralizing rate. In this case, several chassis may be juxtaposed and connected to one another by known quick-coupling systems.

[0017] The effectiveness with which a minefield can be neutralized depends on the operator who may, through oversight, leave uncleared areas. To assist the operator in his task it is possible to determine the position of the feet using sensors connected to a computer so as to record angular and linear values representing parameters governing the position of the articulated arm. Subsequent checking operations can be facilitated by markings on the ground to define the areas which have been made safe.

[0018] In any event, the invention will be clearly understood with the aid of the description which follows, with reference to the appended schematic drawing which, by way of non limiting examples, depicts two embodiments of this device:

[0019]FIG. 1 is a view of a device according to the invention mounted at the end of the arm of a carrier vehicle;

[0020]FIG. 2 is a side view, partly in section, of a first device;

[0021]FIG. 3 is a detailed view on an enlarged scale, partly in section, showing the guidance of a rod associated with an end of a bar in a cylinder;

[0022]FIG. 4 is a detailed view on an enlarged scale and partly in longitudinal section of a bar equipped with a foot for resting on the ground;

[0023]FIG. 5 is a part view in longitudinal section of a second device.

[0024]FIG. 1 depicts a carrier vehicle 2 equipped with an articulated arm 3 the end of which has a support 4 intended for the mounting of a device according to the invention which is denoted by the general reference 5. The device according to the invention comprises a chassis 6 mounted on the support 4 via arms 7 forming a deformable parallelogram. An actuator 8 is mounted between the support 4 and the chassis 6. The chassis 6 has slideways 9 in which a mechanical part 10 known as a proportioning device is mounted so that it can slide vertically, this sliding taking place axially with respect to the chassis, with the travel limited by stops 11, 12. Formed within the proportioning device 10 are a certain number of parallel cylinders 13 running axially with respect to the chassis and open at the bottom. There are, for example, twelve of these cylinders arranged in four rows of three cylinders. These cylinders communicate via an upper chamber 14. The cylinders are filled with an incompressible fluid, such as a hydraulic fluid. Slideably mounted with sealing inside each cylinder is a piston 15 arranged at the end of a rod 16. Means are provided for preventing the rod 16 and the piston 15 from pivoting within the cylinder 13. In the embodiment depicted in the drawing, these rotation-preventing means consist of a longitudinal groove 17 formed in the rod 16, in which a finger 18 carried by the element 19 that closes off the lower end of the cylinder is engaged. This element 19 has a hole for the passage of the rod 16. Resting on this closure element 19 is a helical spring 20 the other end of which bears under the crown of the piston 15. Thus, the piston rods 16 are all aligned when no external influence is exerted on the piston rods.

[0025] The chassis 6 also contains a vibration generator, for example consisting of a percussive hydraulic apparatus of known type, the piston 22 of which is depicted in the drawing, this piston 22, which can move axially, imparting shocks to the proportioning device 10.

[0026] Each piston rod 16 is articulated via a universal joint 23 to the end of a bar 24, longitudinal spring leaves 25, fitted to the rod 16 bearing on the bar 24 to keep it aligned with the rod in the absence of external influences.

[0027] Each bar 24 is equipped at its lower end with a rod 26 fixed rigidly and removeably in line with the bar 24. This rod, which is tubular, in the embodiment depicted in FIG. 4, is made of a low-cost material and is readily breakable. It may, for example, be a synthetic substance or, alternatively, bamboo.

[0028] Articulated via a universal joint 27 to the lower end of each rod 26 is a flat foot 28, for example of rectangular shape, intended to rest on the ground. It may be noted that a casing 29 secured to the chassis 6 extends the latter downward and protects the cylinders 13, the pistons 15, the piston rods 16 and, partially, the bars 24.

[0029]FIG. 5 depicts an alternative form of embodiment of the device described previously, in which the same elements are denoted by the same references. In this case, the various feet 28 are joined to one another by flexible links 30 and the feet situated at the periphery ate connected by links 32 to a frame 33 that extends the casing 29 downward.

[0030] The result of the structure that has just been described is that the axial pressing force produced by the actuator 7 is transmitted directly to the chassis 6 then to the proportioning device 10 via the stops 12, this pressure then being transmitted to the feet 28 via the incompressible fluid contained in the cylinders 13, via the bars 24 and via the rods 26. As far as the vibration produced by the generator the piston 22 of which is depicted in the drawing is concerned, this is transmitted directly to the proportioning device 10 and to the fluid it contains then, in succession, to the pistons 15, the bars 24, 26 and the feet 28.

[0031] As shown in the drawing, particularly in FIG. 4, articulating the bars 24, 26 with respect to the piston rods 16 allows the bars to become inclined to suit the nature of the land. It is thus possible, by virtue of this device, to operate on land which is far more irregular than in the case where the bars are aligned permanently with the piston rods. Furthermore, in the case of the device depicted in FIG. 5, it is possible for the device to be moved over the land while it is operating, that is to say while continuing to exert pressure via the ram 18 and vibration via the vibration generator.

[0032] As goes without saying, the invention is not restricted solely to the embodiments of this device which have been described hereinabove by way of example; on the contrary, it encompasses all alternative forms thereof. Thus, in particular, several devices could be juxtaposed or, alternatively, the means of preventing the pistons from rotating and the elastic means of upward return of the pistons mounted in the cylinders 13 could differ without thereby departing from the scope of the invention. 

1. A device for neutralizing a minefield, of the type mounted on a carrier vehicle equipped with at least one support (4) to which a chassis (6) is articulated with the interposition of a pressure actuator (8), the chassis being equipped at its lower end with a plurality of vertical bars (24) the lower ends (26) of which are provided with feet (28) and the upper ends of which are each provided with a piston (15) mounted to slide in a cylinder (13), the various cylinders communicating and being filled with an incompressible fluid subjected to the action of a vibration generator (22) contained in the chassis, characterized in that a mechanical part (10) known as a proportioning device, in which the cylinders (13) used for mounting the pistons (15) arranged at the upper ends of the bars (24) are formed and which incorporates a chamber (14) for placing these cylinders in communication, is mounted to slide between stops (11, 12) in the chassis, parallel to the axes of the cylinders (13), the mechanical part forming a proportioning device (10) being subjected directly to the action of the pressing forces of the actuator (8), via the stops (12) of the chassis.
 2. The device as claimed in claim 1, characterized in that the proportioning device (10) is in direct contact with the vibration generator (22) which transmits vibration parallel to the axis of the cylinders.
 3. The device as claimed in one of claims 1 and 2, characterized in that each piston rod (16) is articulated via a universal joint (23) to the upper end of a bar (24), longitudinal spring leaves (25) fitted to the rod (16) bearing on the bar (24) to keep it aligned with the rod (16) in the absence of external influences.
 4. The device as claimed in one of claims 1 to 3, characterized in that each piston rod (16) is prevented from rotating with respect to the cylinder (13) in which the piston (15) it bears is moveably mounted.
 5. The device as claimed in one of claims 1 to 4, characterized in that each piston rod (16) is subjected to the action of a spring (20) exerting, on the rod, an upward vertical action so as to align the feet (28) of the various bars (24, 26) when no influence is exerted on the bars.
 6. The device as claimed in one of claims 1 to 5, characterized in that each bar (24, 26) bearing a foot (28) is made as two rigid parts, that is to say an upper part (24) mounted on the piston rod (16) and a lower part (26) or rod which, fixed rigidly and removably in line with the upper part, is made of a readily-breakable and low-cost material.
 7. The device as claimed in one of claims 1 to 6, characterized in that the feet (28) are joined to one another by flexible links (30), the feet (28) arranged at the periphery themselves being connected by such links (32) to a frame (33) or casing that extends the chassis (6) downward. 